I have been playing with Opera's debugger. Everything works as it should until this code gets run ...
Code:
http://r.skimresources.com/api/?callback=skimlinksApplyHandlers&data=%7B%22pubcode%22%3A%2261076X1383750%22%2C%22domains%22%3A%5B%22scitechforum.com%22%2C%22happypetforum.com%22%2C%22greengardenforum.com%22%2C%22tdpforum.com%22%2C%22goodfoodforum.com%22%2C%22craftycustard.com%22%2C%22stylishvenus.com%22%2C%22xenforo.com%22%2C%22clickfinity.net%22%2C%22cyclingwebsitesdirectory.com%22%2C%22theforumsdirectory.com%22%2C%22cyclingwebsearch.com%22%5D%2C%22page%22%3A%22http%3A%2F%2Fwww.cyclechat.net%2Fforums%2Fsite-support.29%2F%22%7D
The browser then goes into meltdown. (The data used in the call will vary from thread to thread according to what links are on the page.)
This does not happen in other parts of the forum, so something is interacting with something else inside threads ...
Further investigation has shown that the meltdown does not occur inside locked threads, and the only difference that I can think of is that there is no post edit box displayed in locked threads.
Signature tickers do not seem to make any difference - I can find seized-up threads with no tickers, and quick locked threads which do contain tickers.